GoForSmoke:
220R is 220 Ohms Resistance abbreviation. you can add resistances by wiring them in serial. 2 100 ohm resistors in line is close enough to 220R for this to work.IO is an Input-Output pin. The pins you setMode() as OUTPUT, INPUT or INPUT_PULLUP as opposed to 5V, GND, 3V3, reset, and the clock pins. 3V3 is 3.3V and in case you're wondering, I didn't make this up!
Thank you very much for your explanation, it makes sense! I'll see if I have any 100 ohm resistors. Do you know what the difference between the 220E 220R and 220K resistors are?